An article published in the journal “Nature Astronomy” reports the discovery of new structures in the Fomalhaut star system. A team of researchers led by András Gáspár of the University of Arizona used the James Webb Space Telescope and found a new ring of dust and gas that adds to the two already known. The new ring is separated from the outer one by an already-known gap and from the inner one by a newly-found gap. The new gap was probably generated by gravitational perturbations that could indicate the presence of a planet or could have been produced by the formation of a dust cloud that occurred recently.
The image (NASA, ESA, CSA. Elaboration: András Gáspár (University of Arizona), Alyssa Pagan (STScI). Science: András Gáspár (University of Arizona)) shows Fomalhaut and the disks of gas and dust that surround it as seen by the James Webb Space Telescope’s Mid-Infrared Instrument (MIRI). Around the star, it’s now possible to see the inner disk, the inner gap, the intermediate belt, the outer gap, the outer ring, the halo surrounding the circumstellar disk, and the Great Dust Cloud.
Fomalhaut A, as the main star of a triple system is technically called, is young, although according to a 2012 study, it’s about 440 million years old, and has a mass that is about twice the Sun’s. Previous studies showed, thanks to the Hubble Space Telescope and the ALMA radio telescope, two rings of gas and dust but also debris probably generated by collisions between comets. For years there were discussions of the possible identification of a planet but the improvement of exoplanet detection techniques led to growing doubts up to the point of discarding that possibility even though the possibility that the system contains planets wasn’t ruled out.
The James Webb Space Telescope has once again made it possible to observe a cosmic object obtaining details never seen before. In the case of the Fomalhaut system, it made it possible to detect a new ring of gas and dust between the two already known. It’s separated from the inner ring by a gap that was never observed before even though it has a width that is about ten times the distance between the Earth and the Sun.
Clouds of gas and debris seem so common in the Fomalhaut system because the James Webb Space Telescope discovered what the researchers dubbed the Great Dust Cloud. It’s probably the consequence of the collision between two icy bodies that generated debris that later collided again with each other until they fragmented into small particles.
A ring of debris probably generated by comet collisions was already known, and the presence of a debris cloud indicates that several catastrophic events took place in the Fomalhaut system. The asteroid belt and the Kuiper belt in the solar system could have similarities with certain structures in the Fomalhaut system and it will be interesting to study those debris to understand if they can lead to the formation of new more or less large objects.
The new observations led to new confirmations that what looked like a planet was actually probably another cloud of gas and dust. However, the complexity of the structures present around Fomalhaut with various gaps between the rings could be due to the presence of planets still hidden in gas and dust and for this reason invisible even to the James Webb Space Telescope.
The new discoveries add to the previous ones forming a complex picture. It’s for this reason that the researchers say Fomalhaut appears to be the site of a planetary system that may be dynamically active. The possible presence of planets is still to be verified and certainly, the studies of this very interesting system will continue.
